What should I do now?

I met a girl on a dating app recently and we ended up talking for almost two hours on the first call. During the conversation she opened up a lot about her life, especially problems related to her parents and her career. I mostly listened and tried to be supportive, and overall the conversation felt very genuine. She also seemed sweet and comfortable while talking. Last night I asked her if she was free so we could talk again, but she hasn’t replied yet. Now I’m not sure what to think. I don’t want to come across as pushy by sending another message, but at the same time I’m wondering if I should follow up or just wait.